In recent years, in view of reduction of the environmental burden, various attempts have been carried out to securely achieve pesticidal effects while the amount or the number of agricultural chemicals used is reduced. One method is to enhance the effects by addition of adjuvants.
As adjuvants, usually, a nonionic surfactant such as a polyoxyethylene alkylphenyl ether, a polyoxyethylene alkyl ether or a polyoxyethylene higher fatty acid ester, or an organic silicone type surfactant is used, and particularly an organic silicone type surfactant is known to have excellent effects by virtue of its low toxicity and high surfactant potency. However, a diluted solution (spray solution) of an agricultural chemical having such a spreader added has a lowered surface tension and is thereby likely to foam, such being problematic when used. Accordingly, an antifoaming agent is added for the purpose of preventing foaming when an aqueous dispersion of an agricultural chemical is prepared, however, it is very difficult to completely suppress foaming even by addition of an antifoaming agent since an organic silicone type surfactant has high surfactant potency.